erkbd - Eriks Keyboard

Erkbd is a 3D printed, handwired 44 key split keyboard powered by qmk.

It features two encoders, two 1.3" 128x64 oled displays, and uses the waveshare rp2040zero development board.

It is inspired primarily by crkbd together with the layout of the void ergo s

The keyboard was designed using FreeCAD and printed using a Creality Ender 3v3 ke 3D printer using creality CR PLA filament.

The name ERiks KeyBoarD is ment to honor corne (crkbd), which pulled me down this money burning rabbit hole combined with the fact that my name is Erik.

Images

The knife was a short but intense meme on reddit.com/r/ErgoMechKeyboards they are not included.

Issues and things to be aware of before building

If you decide to build this be aware that this was my first 3D modeling project with no previous CAD experience. It is not perfect and there are a few issues listed here.

Case dimensions

For aesthic reasons I wanted the caps to be as close as possible to the case edge, it took some trial and error before getting it right. Printing with another printer or using other keycaps may cause the caps to hit the edge.

Before soldering, assemble the case and plate with switches and keycaps along the border and make sure the keycaps stay clear of the case.

You might be able to just sand the edges a little but let me know if it doesnt fit properly, and i will try to fix a new version with a larger gap.

Controller mount

The edges of the controller mount was too low in the first revision and i ended up having to use more hot glue than i would have liked to secure them. I have raised them a little and now the controllers should fit better and stay in place with just friction but i have not tried this this out since i have no more controllers.

Switch holes

The plate is 3mm thick but has pockets for the switches to click in. They fit well enough for regular use but if you plan to change keycaps i recomend putting some hot glue on each switch to secure them or be very careful when pulling the caps to not damage the matrix

Bumpers

To keep the profile low and avoid the screws from hitting each other in the middle of the spacers there are no pockets for the screws on the bottom of the case. Without bumpons they will scratch your desk.

Different OLED PCBs

There are different pcb versions of the sh1106 OLED modules where the pin headers are in slightly different places.

The frame is modeled for the right one in the picture. If you use left (which i did because i wanted white text) you will have to desolder the pin headers and solder wire directly to the pcb from below. The firmware can stay the same.

If you dont want to desolder the headers make sure to get the one to the right in the picture (blue text) then the headers will fit.

Also note that these they have ground and vcc pins reversed.

Spacer positions

The screws for two of the spacers holding the plate up are hidden behind the oled modules. This makes it important to mount these first. Care should also be taken if removing the case so they don't fall out to avoid having to remove the oled frame.

BOM

plate

• ~18g x2 PLA Filament
• 46 pcs mx compatible switches and keycaps
• 2 pcs waveshare rp2040 zero development boards link
• 2 pcs EC11 Rotary encoders link
• 2 pcs DIP PJ320A trrs jacks link
• 44 pcs 1N4148 diodes (or similar) link
• 1 pcs 4.7K resistor link
• Wire for the matrix. I tried using 26 AWG solid core wire i had lying around for everything but found it to thick and ended up wiring the matrix separatly with solid core wire and connect to the controller with thin stranded wire i teared of a ribbon cable.

Case

• ~40g x2 PLA Filament
• 18 pcs 5mm M2 brass female/female spacers and 36 matching screws (18 is a little overkill so some could be skipped) link
• Silicone Bumpons link

Oleds

• ~3g x2 PLA Filament
• 2 pcs 1.3" SH1107 oleds (see note on different versions above) link
• 8 pcs M3*12mm bolts (for mounting the oleds) link
• 8 pcs M3*bolts

Regarding the m3 bolts you can use whichever you want as long as the dimensions match but don't get ugly ones.

Firmware

The keyboard source along with a default and debug keymap can be found in the official qmk_firmware repo here.

The prebuilt firmw